A garment is conventionally produced using an actual or virtual pattern which is used to cut the several fabric workpieces which are conventionally sewn together in a predetermined manner to produce the completed garment. For example, a typical pair of trousers is formed from a right front leg panel, and left front leg panel, a right rear panel and left rear panel, a back panel, a waistband, and one or more pockets. Each of these workpieces has a very different and distinctive shape from the other workpieces used to create a specific garment. Moreover, the dimensions of any specific shaped workpiece will typically be different from one sized garment to another. Automatic cutting machines can be used to mass-produce stacks of workpieces of identical size and shape which can be used in the mass-production of garments. A workpiece or bundle of like workpieces are typically marked with a code or other marking which provides information to the operator regarding the size of the completed garment.
Fashion trends impact how clothes are designed and manufactured. The popularity of denim garments having a faded and worn appearance have caused manufacturers of denim garments to process their fabric in such a ways as to reproduce this look. Initially, denim is a stiff and durable cotton fabric. Sizing, which is added to denim to aid manufacturability, contributes to its stiffness. When denim is worn, the fabric becomes softer and the color fades. Laundering, which washes sizing and dye from the fabric, also softens and fades denim garments.
Various techniques have been used to reproduce the fading and softening that result from normal wear and aging. One conventional technique is stone washing. Stone washing involves mechanically abrading the fabric typically by laundering the denim garments with pumice stones, or the like, in a washing machine. The mechanical contact of the denim with the pumice stones abrades and softens the denim fabric and lightens its color.
Chemical finishing is another technique used to treat fabrics. The garments are mixed in solutions of various chemicals, such as bleaches and enzymes. These chemicals fade the fabric and can also soften it. Chemical finishing usually seeks to simulate the appearance of a "stone washed" fabric. One such chemical patent is U.S. Pat. No. 5,213,581 issued May 25, 1993 to OLSON et al., which discloses an immersion method for fading garments by washing the fabric with cellulase enzyme dissolved in an aqueous bath. The cellulase enzyme bath creates a stone-washed appearance in the fabric.
Because both stone washing and chemical treatment involve agitating the fabric in a tub, the fabric must be treated in its entirety. Treating the fabric as a whole creates two side effects. First, the fabric is typically finished as completed or substantially completed garments. If the fabric was stone washed or chemically treated earlier in the manufacturing process, it would remove the sizing prematurely, making sewing and handling of the fabric more difficult. The patent by OLSON et al. teaches chemical processing of unsewn fabric, but as stated above, finishing the entire fabric before assembling it into garments defeats the purpose of adding sizing.
The second side effect to these finishing techniques is that the fabric is uniformly faded, which is quite different from the localized wear which occurs over time when jeans are worn, and which provides more wear (and more fading) in areas of high wear, with less wear and fading in other areas. Because the garment in conventional finishing is washed as a whole, no part of the garment can receive more or less treatment. To obtain a more natural, localized effect, other mechanical abrasion techniques have been conceived. For example, U.S. Pat. No. 5,593,072 issued Jun. 14, 1997 to HESTER et al., incorporated herein by reference, discloses an automated system for localized finishing of completed garments. A computer and robot performs the finishing process once the completed garment is fitted onto an apparatus that orients the workpiece. Localized abrasion can be carried out by sand blasters, high pressure water, brushes, applicators which spray bleach or enzyme solution, and sand wheels. Although the HESTER patent can achieve localized fading, it requires specialized machinery. Additionally, it requires that the garments be sewn. Abrading sewn garments is problematic because it can weaken important threads that secure the garment pieces together.
A third class of fabric finishing is laser treating. For example, U.S. Pat. No. 5,567,207 issued Oct. 22, 1996 to LOCKMAN et al. discloses an apparatus and method for using lasers to cause photo-decomposition of the coloring agent in a fabric or garment while leaving the underlying textile material undamaged. Although LOCKMAN et al. discloses using a laser to fade dye prior to the fabric being cut and sewn into individual garments, it does not disclose how it can do so in a way which will produce natural looking, localized fading in a completed fabric. In addition, while lasers can be used to fade the dye in denim, the softening that mechanical and chemical abrading produce will apparently not occur following the teachings of LOCKMAN since the textile material is unaffected.
What is needed is an apparatus and method that can be used to produce natural localized fading and abrasion on cut workpieces prior to their being sewn together.